Lignocellulosic biomass fermentation process co-product fuel for cement kiln

ABSTRACT

A fuel made from co-products derived from a lignocellulosic biomass fermentation process is used to fuel a cement production process. Filter cake and syrup co-products are mixed and dried, then burned in a cement kiln to create the temperatures needed for cement production.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of application Ser. No. 14/510,149 filedOct. 9, 2014 which claims priority of U.S. Provisional Applications61/889,061 filed Oct. 10, 2013 and 62/026,059, filed Jul. 18, 2014 eachof which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to the field of fueling a cement process. Morespecifically, a fuel prepared from co-products of a lignocellulosicbiomass fermentation process is used to fuel a cement kiln.

BACKGROUND OF THE INVENTION

Cement is one of the most important and highly used building materialsin the world, being is used in materials such as concrete, mortar,stucco, and many non-specialty grouts. Cement production is highlyenergy intensive, as a temperature of about 1450° C. is required for theprocess. The primary fuel used in making cement is coal, with about 120kg of coal required per ton of cement produced. It has been estimatedthat about 5% of global carbon dioxide emissions originate from cementproduction, 50% of which is from the chemical process and 40% of whichis from burning fuel. The use of coal as fuel releases to the atmospherecarbon that was sequestered underground, producing a net positive gainof carbon to the earth's atmosphere.

Fuel derived from biomass is renewable and is carbon neutral: the sameamount of CO₂ is removed from the atmosphere during growth of thebiomass as is released to the atmosphere upon burning. Thus in contrastto coal, a biomass or biomass-derived fuel does not increase theatmospheric CO₂ burden and so is more environmentally friendly.

A number of waste materials have been used as alternative fuels incement production such as asphalt, plastics, rubber, petcoke, tires, andwaste oils. In addition, agricultural and non-agricultural biomass hasbeen suggested for use as fuel in cement production.

There remains a need for a cement kiln fueling process that makes use ofa fuel that is renewable and more environmentally friendly than coal, aswell as being consistent and reliable.

SUMMARY OF THE INVENTION

The invention relates to the use of a carbon neutral fuel derived fromthe processing of lignocellulosic biomass to fuel cement kilns whichtypically are fueled by coal. Accordingly the invention provides aprocess for fueling a cement process comprising:

a) providing a lignocellulosic filter cake;

b) providing a lignocellulosic syrup;

c) mixing the filter cake of (a) and the syrup of (b) in a filter caketo syrup ratio that is between 1:1 and 9:1 forming a filter cake andsyrup mixture;

d) drying the mixture of (c) producing a filter cake and syrup fuel; and

e) burning the filter cake and syrup fuel in a cement kiln containingcement raw material.

Additionally the invention provides a cement composition comprising ashfrom burned material selected from the group consisting of filter cakeand syrup fuel, filter cake, syrup, and mixtures thereof.

In another aspect the invention provides a concrete compositioncomprising ash from burned material selected from the group consistingof filter cake and syrup fuel, filter cake, syrup, and mixtures thereof.

In another aspect of the invention a process for the production ofcement is provided comprising:

a) providing a limestone composition wherein the limestone compositionoptionally comprises one or more of clay, shale, silica, sand bauxite,iron ore, fly ash, and slag;

b) optionally grinding the limestone composition of a);

c) heating the limestone composition of a) or b) in a kiln to atemperature of at least about 600° C. wherein fuel is added to the kilnin the presence of the limestone e composition wherein clinker isproduced; and

d) cooling and recovering the clinker from the kiln; wherein the fueladded to the kiln at step c) is comprised of a lignocellulosicco-product selected from the group consisting of filter cake and syrupfuel, filter cake, syrup, and mixtures thereof.

DETAILED DESCRIPTION

The following definitions and abbreviations are to be used for theinterpretation of the claims and the specification.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having,” “contains” or “containing,” or any othervariation thereof, are intended to cover a non-exclusive inclusion. Forexample, a composition, a mixture, process, method, article, orapparatus that comprises a list of elements is not necessarily limitedto only those elements but may include other elements not expresslylisted or inherent to such composition, mixture, process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

The indefinite articles “a” and “an” preceding an element or componentof the invention are intended to be nonrestrictive regarding the numberof instances (i.e. occurrences) of the element or component. Therefore“a” or “an” should be read to include one or at least one, and thesingular word form of the element or component also includes the pluralunless the number is obviously meant to be singular.

The term “invention” or “present invention” as used herein is anon-limiting term and is not intended to refer to any single embodimentof the particular invention but encompasses all possible embodiments asdescribed in the specification and the claims.

As used herein, the term “about” modifying the quantity of an ingredientor reactant of the invention employed refers to variation in thenumerical quantity that can occur, for example, through typicalmeasuring and liquid handling procedures used for making concentrates oruse solutions in the real world; through inadvertent error in theseprocedures; through differences in the manufacture, source, or purity ofthe ingredients employed to make the compositions or carry out themethods; and the like. The term “about” also encompasses amounts thatdiffer due to different equilibrium conditions for a compositionresulting from a particular initial mixture. Whether or not modified bythe term “about”, the claims include equivalents to the quantities. Inone embodiment, the term “about” means within 10% of the reportednumerical value, preferably within 5% of the reported numerical value.

The term “lignocellulosic” refers to a composition comprising bothlignin and cellulose. Lignocellulosic material may also comprisehemicellulose.

The term “cellulosic” refers to a composition comprising cellulose andadditional components, including hemicellulose.

The term “lignocellulosic biomass” refers to any lignocellulosicmaterial and includes materials comprising cellulose, hemicellulose,lignin, starch, oligosaccharides and/or monosaccharides. Biomass mayalso comprise additional components, such as protein and/or lipid.Biomass may be derived from a single source, or biomass can comprise amixture derived from more than one source; for example, biomass couldcomprise a mixture of corn cobs and corn stover, or a mixture of grassand leaves. Lignocellulosic biomass includes, but is not limited to,bioenergy crops, agricultural residues, municipal solid waste,industrial solid waste, sludge from paper manufacture, yard waste, woodand forestry waste. Examples of biomass include, but are not limited to,corn cobs, crop residues such as corn husks, corn stover, grasses(including Miscanthus), wheat straw, barley straw, hay, rice straw,switchgrass, waste paper, sugar cane bagasse, sorghum plant material,soybean plant material, components obtained from milling of grains orfrom using grains in production processes (such as DDGS: drieddistillers grains with solubles), woody material such as trees,branches, roots, wood chips, sawdust, shrubs and bushes, leaves,vegetables, fruits, flowers, empty palm fruit bunch, and energy cane.

The term “energy cane” refers to sugar cane that is bred for use inenergy production. It is selected for a higher percentage of fiber thansugar.

The term “lignocellulosic biomass hydrolysate” refers to the productresulting from saccharification of lignocellulosic biomass. The biomassmay also be pretreated or pre-processed prior to saccharification.

The term “pretreated biomass” means biomass that has been subjected topretreatment prior to saccharification. The pretreatment may take theform of physical, thermal or chemical means and combinations thereof.

The term “saccharification” refers to the production of fermentablesugars from polysaccharides.

The term “butanol” refers to isobutanol, 1-butanol, 2-butanol, orcombinations thereof.

The term “lignocellulosic biomass hydrolysate fermentation broth” isbroth containing product resulting from biocatalyst growth andproduction in a medium comprising lignocellulosic biomass hydrolysate.This broth includes components of lignocellulosic biomass hydrolysatethat are not consumed by the biocatalyst, as well as the biocatalystitself and product made by the biocatalyst.

The term “slurry” refers to a mixture of insoluble material and aliquid. A slurry may also contain a high level of dissolved solids.Examples of slurries include a saccharification broth, a fermentationbroth, and a stillage.

The term “whole stillage” refers to the bottoms of a distillation. Thewhole stillage contains the high boilers and any solids of adistillation feed stream. Whole stillage is a type of depleted broth.Whole stillage is a type of product depleted fermentation broth.

The term “thin stillage” refers to a liquid fraction resulting fromsolid/liquid separation of a fermentation broth, or product depletedfermentation broth (such as whole stillage).

The term “product depleted broth” or “depleted broth” refers herein to alignocellulosic biomass hydrolysate fermentation broth after removal ofa product stream.

The term “syrup” means a concentrated product produced from the removalof water, generally by evaporation, from thin stillage.

The term “filter cake” refers to a product remaining after removal ofwater from fermentation broth, or product depleted fermentation broth(such as whole stillage).

The term “target product” refers to any product that is produced by amicrobial production host cell in a fermentation. Target products may bethe result of genetically engineered enzymatic pathways in host cells ormay be produced by endogenous pathways. Typical target products includebut are not limited to acids, alcohols, alkanes, alkenes, aromatics,aldehydes, ketones, biopolymers, proteins, peptides, amino acids,vitamins, antibiotics, and pharmaceuticals.

The term “fermentation” refers broadly to the use of a biocatalyst toproduce a target product. Typically the biocatalyst grows in afermentation broth utilizing a carbon source in the broth, and throughits metabolism produces a target product.

The term “solid lignocellulosic fuel composition” refers to a mixture oflignocellulosic syrup and an additional fuel component. It includes aninitial mixture of these components, as well as the mixture at any stagefollowing mixing. It thus includes the composition during and afterprocessing to form a readily handled fuel material.

“Solids” refers to soluble solids and insoluble solids. Solids from alignocellulosic fermentation process contain residue from thelignocellulosic biomass used to make hydrolysate medium.

“Volatiles” refers herein to components that will largely be vaporizedin a process where heat is introduced. Volatile content is measuredherein by establishing the loss in weight resulting from heating underrigidly controlled conditions to 950° C. (as in ASTM D-3175). Typicalvolatiles include, but are not limited to, hydrogen, oxygen, nitrogen,acetic acid, and some carbon and sulfur.

“Fixed carbon” refers herein to a calculated percentage made by summingthe percent of moisture, percent of ash, and percent of volatile matter,and then subtracting that percent from 100.

“Ash” is the weight of the residue remaining after burning undercontrolled conditions according to ASTM D-3174.

“Sugars” as referred to in the lignocellulosic syrup composition means atotal of monosaccharides and soluble oligosaccharides.

Provided herein is a process for fueling a cement process which makesuse of a fuel that is renewable and more environmentally friendly thancoal. With the growing cellulosic ethanol industry, this fuel will be aconsistent and reliable fuel source.

In the process for preparing cement, cement raw material is heated in acement kiln to very high temperatures. Cement raw material includes anymaterials that are added to a cement kiln for cement production. Themajor cement raw material is limestone. Additional materials may beincluded in the cement raw material in a cement kiln such as clay,shale, sand (typically silica), bauxite, iron ore, fly ash, and/or slag.Typically, a mixture of limestone and one or more additional material ismade to provide cement raw material in a cement kiln. In variousembodiments the cement raw material contains limestone along with clay,shale, sand (typically silica), bauxite, iron ore, fly ash, slag, or anymixture of these materials. Typically the mixture is ground and fed intothe kiln where it is gradually heated by combusting fuel.

A temperature that is above 600° C. is needed for calcination of thelimestone, which is the reaction shown in (I).

CaCO₃->CaO+CO₂   (I)

A fusion temperature of about 1,450° C. is then needed to sinter thecement raw material into clinker.

Fuel is added into the cement kiln and is burned in the presence of thecement raw material. Any ash produced by burning of the fuel ends up inthe clinker as a secondary raw material.

For example in a rotary cement kiln, a flame of burning fuel is in thelower part of a kiln tube which is slightly tilted and slowly rotated.Cement raw material is fed into the upper end of the kiln tube. Rotationof the kiln tube causes the cement raw material to slowly move downtowards the lower end where it is heated, undergoing calcination andsintering. Then the produced clinker exits at the lower end into acooler. Air is drawn through the cooler, where the air temperature israised by the cooling clinker, then the heated air enters the kilncausing rapid combustion of fuel.

In the present process, the fuel that is burned in a cement kilncontaining cement raw material is made from filter cake and syrupco-products produced in a lignocellulosic biomass fermentation process.The lignocellulosic biomass fermentation process is one that useslignocellulosic biomass as a source of fermentable sugars which are usedas a carbon source for a biocatalyst. The biocatalyst uses the sugars ina fermentation process to produce a target product.

To produce fermentable sugars from lignocellulosic biomass, the biomassis treated to release sugars such as glucose, xylose, and arabinose fromthe polysaccharides of the biomass. Lignocellulosic biomass may betreated by any method known by one skilled in the art to producefermentable sugars in a hydrolysate. Typically the biomass is pretreatedusing physical, thermal and/or chemical treatments, and saccharifiedenzymatically. Thermo-chemical pretreatment methods include steamexplosion or methods of swelling the biomass to release sugars (see forexample WO2010113129; WO2010113130). Chemical saccharification may alsobe used. Physical treatments for pre-processing the biomass include, butare not limited to, grinding, milling, and cutting. Physical treatmentssuch as these may be used for particle size reduction prior to furtherchemical treatment. Chemical treatments include base treatment such aswith strong base (ammonia or NaOH), or acid treatment (U.S. Pat. No.8,545,633; WO2012103220). In one embodiment the biomass is treated withammonia (U.S. Pat. No. 7,932,063; U.S. Pat. No. 7,781,191; U.S. Pat. No.7,998,713; U.S. Pat. No. 7,915,017). These treatments release polymericsugars from the biomass. Particularly useful is a low ammoniapretreatment where biomass is contacted with an aqueous solutioncomprising ammonia to form a biomass-aqueous ammonia mixture where theammonia concentration is sufficient to maintain alkaline pH of thebiomass-aqueous ammonia mixture but is less than about 12 weight percentrelative to dry weight of biomass, and where dry weight of biomass is atleast about 15 weight percent solids relative to the weight of thebiomass-aqueous ammonia mixture, as disclosed in U.S. Pat. No.7,932,063, which is herein incorporated by reference.

Saccharification, which converts polymeric sugars to monomeric sugars,may be either by enzymatic or chemical treatments. The pretreatedbiomass is contacted with a saccharification enzyme consortium undersuitable conditions to produce fermentable sugars. Prior tosaccharification, the pretreated biomass may be brought to the desiredmoisture content and treated to alter the pH, composition or temperaturesuch that the enzymes of the saccharification enzyme consortium will beactive. The pH may be altered through the addition of acids in solid orliquid form. Alternatively, carbon dioxide (CO₂), which may be recoveredfrom fermentation, may be utilized to lower the pH. For example, CO₂ maybe collected from a fermenter and fed into the pretreatment productheadspace in the flash tank or bubbled through the pretreated biomass ifadequate liquid is present while monitoring the pH, until the desired pHis achieved. The temperature is brought to a temperature that iscompatible with saccharification enzyme activity, as noted below.Typically suitable conditions may include temperature between about 40°C. and 50° C. and pH between about 4.8 and 5.8.

Enzymatic saccharification of cellulosic or lignocellulosic biomasstypically makes use of an enzyme composition or blend to break downcellulose and/or hemicellulose and to produce a hydrolysate containingsugars such as, for example, glucose, xylose, and arabinose.Saccharification enzymes are reviewed in Lynd, L. R., et al. (Microbiol.Mol. Biol. Rev., 66:506-577, 2002). At least one enzyme is used, andtypically a saccharification enzyme blend is used that includes one ormore glycosidases. Glycosidases hydrolyze the ether linkages of di-,oligo-, and polysaccharides and are found in the enzyme classificationEC 3.2.1.x (Enzyme Nomenclature 1992, Academic Press, San Diego, Calif.with Supplement 1 (1993), Supplement 2 (1994), Supplement 3 (1995,Supplement 4 (1997) and Supplement 5 [in Eur. J. Biochem., 223:1-5,1994; Eur. J. Biochem., 232:1-6, 1995; Eur. J. Biochem., 237:1-5, 1996;Eur. J. Biochem., 250:1-6, 1997; and Eur. J. Biochem., 264:610-650 1999,respectively]) of the general group “hydrolases” (EC 3.). Glycosidasesuseful in saccharification can be categorized by the biomass componentsthey hydrolyze. Glycosidases useful in saccharification may includecellulose-hydrolyzing glycosidases (for example, cellulases,endoglucanases, exoglucanases, cellobiohydrolases, β-glucosidases),hemicellulose-hydrolyzing glycosidases (for example, xylanases,endoxylanases, exoxylanases, β-xylosidases, arabino-xylanases, mannases,galactases, pectinases, glucuronidases), and starch-hydrolyzingglycosidases (for example, amylases, α-amylases, β-amylases,glucoamylases, α-glucosidases, isoamylases). In addition, it may beuseful to add other activities to the saccharification enzyme consortiumsuch as peptidases (EC 3.4.x.y), lipases (EC 3.1.1.x and 3.1.4.x),ligninases (EC 1.11.1.x), or feruloyl esterases (EC 3.1.1.73) to promotethe release of polysaccharides from other components of the biomass. Itis known in the art that microorganisms that producepolysaccharide-hydrolyzing enzymes often exhibit an activity, such as acapacity to degrade cellulose, which is catalyzed by several enzymes ora group of enzymes having different substrate specificities. Thus, a“cellulase” from a microorganism may comprise a group of enzymes, one ormore or all of which may contribute to the cellulose-degrading activity.Commercial or non-commercial enzyme preparations, such as cellulase, maycomprise numerous enzymes depending on the purification scheme utilizedto obtain the enzyme. Many glycosyl hydrolase enzymes and compositionsthereof that are useful for saccharification are disclosed in WO2011/038019. Additional enzymes for saccharification include, forexample, glycosyl hydrolases that hydrolyze the glycosidic bond betweentwo or more carbohydrates, or between a carbohydrate and anoncarbohydrate moiety.

Saccharification enzymes may be obtained commercially. Such enzymesinclude, for example, Spezyme® CP cellulase, Multifect® xylanase,Accelerase® 1500, Accellerase® DUET, and Accellerase® Trio™(Dupont™/Genencor®, Wilmington, Del.), and Novozyme-188 (Novozymes, 2880Bagsvaerd, Denmark). In addition, saccharification enzymes may beunpurified and provided as a cell extract or a whole cell preparation.The enzymes may be produced using recombinant microorganisms that havebeen engineered to express one or more saccharifying enzymes. Forexample, an H3A protein preparation that may be used forsaccharification of pretreated cellulosic biomass is an unpurifiedpreparation of enzymes produced by a genetically engineered strain ofTrichoderma reesei, which includes a combination of cellulases andhemicellulases and is described in WO 2011/038019, which is incorporatedherein by reference.

Chemical saccharification treatments may be used and are known to oneskilled in the art, such as treatment with mineral acids including HCland H₂SO₄ (U.S. Pat. No. 5,803,89; WO2011002660)

Sugars such as glucose, xylose and arabinose are released bysaccharification of lignocellulosic biomass and these monomeric sugarsprovide a carbohydrate source for a biocatalyst used in a fermentationprocess. The sugars are present in a biomass hydrolysate that is used asfermentation medium. The fermentation medium may be composed solely ofhydrolysate, or may include components additional to the hydrolysatesuch as sorbitol or mannitol at a final concentration of about 5 mM asdescribed in U.S. Pat. No. 7,629,156, which is incorporated herein byreference. The biomass hydrolysate typically makes up at least about 50%of the fermentation medium. Typically about 10% of the final volume offermentation broth is seed inoculum containing the biocatalyst.

The medium comprising hydrolysate is fermented in a fermenter, which isany vessel that holds the hydrolysate fermentation medium and at leastone biocatalyst, and has valves, vents, and/or ports used in managingthe fermentation process.

Any biocatalyst that produces a target product utilizing glucose andpreferably also xylose, either naturally or through genetic engineering,may be used for fermentation of the fermentable sugars in the biomasshydrolysate made from lignocellulosic biomass. Target products that maybe produced by fermentation include, for example, acids, alcohols,alkanes, alkenes, aromatics, aldehydes, ketones, biopolymers, proteins,peptides, amino acids, vitamins, antibiotics, and pharmaceuticals.Alcohols include, but are not limited to methanol, ethanol, propanol,isopropanol, butanol, ethylene glycol, propanediol, butanediol,glycerol, erythritol, xylitol, mannitol, and sorbitol. Acids may includeacetic acid, formic acid, lactic acid, propionic acid,3-hydroxypropionic acid, butyric acid, gluconic acid, itaconic acid,citric acid, succinic acid, 3-hydroxyproprionic acid, fumaric acid,maleic acid, and levulinic acid. Amino acids may include glutamic acid,aspartic acid, methionine, lysine, glycine, arginine, threonine,phenylalanine and tyrosine. Additional target products include methane,ethylene, acetone and industrial enzymes.

The fermentation of sugars in biomass hydrolysate to target products maybe carried out by one or more appropriate biocatalysts, that are able togrow in medium containing biomass hydrolysate, in single or multistepfermentations. Biocatalysts may be microorganisms selected frombacteria, filamentous fungi and yeast. Biocatalysts may be wild typemicroorganisms or recombinant microorganisms, and may include, forexample, organisms belonging to the genera of Escherichia, Zymomonas,Saccharomyces, Candida, Pichia, Streptomyces, Bacillus, Lactobacillus,and Clostridiuma. Typical examples of biocatalysts include recombinantEscherichia coli, Zymomonas mobilis, Bacillus stearothermophilus,Saccharomyces cerevisiae, Clostridia thermocellum, Thermoanaerobacteriumsaccharolyticum, and Pichia stipitis. To grow well and have high productproduction in a lignocellulosic biomass hydrolysate fermentation broth,a biocatalyst may be selected or engineered to have higher tolerance toinhibitors present in biomass hydrolysate such as acetate. For example,the biocatalyst may produce ethanol as a target product, such asproduction of ethanol by Zymomonas mobilis as described in U.S. Pat. No.8,247,208, which is incorporated herein by reference.

Fermentation is carried out with conditions appropriate for theparticular biocatalyst used. Adjustments may be made for conditions suchas pH, temperature, oxygen content, and mixing. Conditions forfermentation of yeast and bacterial biocatalysts are well known in theart.

In addition, saccharification and fermentation may occur at the sametime in the same vessel, called simultaneous saccharification andfermentation (SSF). In addition, partial saccharification may occurprior to a period of concurrent saccharification and fermentation in aprocess called HSF (hybrid saccharification and fermentation).

For large scale fermentations, typically a smaller culture of thebiocatalyst is first grown, which is called a seed culture. The seedculture is added to the fermentation medium as an inoculum typically inthe range from about 2% to about 20% of the final volume.

Typically fermentation by the biocatalyst produces a fermentation brothcontaining the target product made by the biocatalyst. For example, inan ethanol process the fermentation broth may be a beer containing fromabout 6% to about 10% ethanol. In addition to target product, thefermentation broth contains water, solutes, and solids from thehydrolysate medium and from biocatalyst metabolism of sugars in thehydrolysate medium. Typically the target product is isolated from thefermentation broth producing a depleted broth, which may be called wholestillage. For example, when ethanol is the product, the broth isdistilled, typically using a beer column, to generate an ethanol productstream and a whole stillage. Distillation may be using any conditionsknown to one skilled in the art including at atmospheric or reducedpressure. The distilled ethanol is further passed through arectification column and molecular sieve to recover an ethanol product.The target product may alternatively be removed in a later step such asfrom a solid or liquid fraction after separation of fermentation broth.

The syrup and filter cake co-products of a lignocellulosic biomassfermentation process are produced from the fermentation broth ordepleted fermentation broth. An example of syrup production is disclosedin U.S. Pat. No. 8,721,794, which is incorporated herein by reference.The broth or depleted broth, such as whole stillage, is separated intosolid and liquid streams, where the liquid stream is called thinstillage. Various filtration devices may be used such as a belt filter,belt press, screw press, drum filter, disc filter, Nutsche filter,filter press or filtering centrifuge. Filtration may be aided such as byapplication of vacuum, pressure, or centrifugal force. To improveefficiency of filtration, a heat treatment may be used as disclosed incommonly owned and co-pending US20120178976, which is incorporatedherein by reference.

A product stream may be removed following liquid/solid filtration of alignocellulosic biomass hydrolysate fermentation broth. For example, theliquid stream may be extracted or distilled to generate a productstream, such as distillation to produce an ethanol product stream and aremaining liquid.

Following liquid/solid separation of a lignocellulosic biomasshydrolysate fermentation broth or depleted broth the liquid fraction isfurther purified by evaporation producing water that may be recycled anda syrup. Prior to evaporation, a portion of the liquid fraction may berecycled for use as back set, which may be added at any point in theprocess where water is needed, such as in pretreatment,saccharification, or biocatalyst seed production. Evaporation may be inany evaporation system, such as falling film, rising film, forcedcirculation, plate or mechanical and thermal vapor recompressionsystems. Evaporation may be continuous or batch and may use amulti-effect evaporator. The evaporated water may be recycled in theoverall lignocellulosic biomass hydrolysate fermentation process.

The remaining material after evaporation is a syrup which is the presentlignocellulosic syrup. The lignocellulosic syrup composition containsfrom about 40% to about 70% solids (may have about 40%, 45%, 50%, 55%,60%, 65%, or 70% solids), from about 10 g/l to 30 g/l of acetamide, atleast about 40 g/l of sugars, a density of about 1 to about 2 g/cm³, andviscosity less than 500 SSU at 100° F. (38° C.). “SSU” is SayboltUniversal Viscosity in Seconds (Burger VL., Encycl. Ind. Chem. Anal.(1966), Volume 3, 768-74). When biomass is treated with ammonia, thelignocellulosic syrup contains at least about 5 g/l of ammonia.

Following liquid/solid separation of a lignocellulosic biomasshydrolysate fermentation broth or depleted broth (such as wholestillage) the solids fraction is the present lignocellulosic filter cake(also called wetcake). The wet lignocellulosic filter cake compositioncontains from about 35% to 65% moisture, or from about 40% to about 60%moisture (may have about 35%, 40%, 45%, 50%, 55%, 60%, or 65% moisture),from about 20% to about 75% volatiles or about 20% to about 40%volatiles (may have about 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%,65%, or 75% volatiles), from about 35% to 65% solids or from about 40%to about 60% solids (may have about 35%, 40%, 45%, 50%, 55%, 60%, or 65%solids), from about 1% to about 30% ash, or from about 3% to about 30%ash (may have about 1%, 3%, 5%, 10%, 15%, 20%, 25%, or 30% ash), fromabout 5% to about 20% fixed carbon, and it has an energy value of about2,000 to about 9,000 BTU/lb (may have about 2,000, 2,500, 3,000, 3,500,4,000, 4,500, 5,000, 5,500, 6,000, 6,500, 7,000, 7,500, 8,000, 8,500, or9,000 BTU/lb). The volatile content is measured by establishing the lossin weight resulting from heating under rigidly controlled conditions to950° C. (as in ASTM D-3175). Typical volatiles include hydrogen, oxygen,nitrogen, acetic acid, and some carbon and sulfur. Ash is determined byweighing the residue remaining after burning under controlled conditionsaccording to ASTM D-3174. The amount of fixed carbon is calculated byadding the percentages of moisture, ash, and volatiles, and thensubtracting from 100. The full upper range of BTU/lb is typicallyachieved with drying.

The present fuel is produced by mixing lignocellulosic filter cake andlignocellulosic syrup in a ratio that is between about 1:1 and about 9:1forming a filter cake and syrup mixture. The ratio may be 1:1. 1.5:1,2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1,8:1, 8.5:1, or 9:1. The filter cake may be size reduced prior to mixingwith syrup. For example, a delumper may be used to reduce the size ofclumps of filter cake. Typically the components are added togetherslowly or in increments while mixing to avoid clumping. Any type ofmixer that accommodates wet feed may be used such as a paddle mixer, ascrew mixer, or a mixer truck.

Pre-dried material may be included in the filter cake and syrup mixture.Pre-dried material may be filter cake that is previously dried, orfilter cake and syrup mixture that is previously dried. Pre-dried filtercake may have a moisture content of about 20% or less.

The mixture of filter cake, syrup, and optionally pre-dried material isdried to achieve a moisture content of from about 8% to about 20% usingany suitable type of dryer, to form a filter cake and syrup fuel. Forexample, the moisture content may be 8%, 9%, 10%, 11%, 12%, 13%, 14%,16%, 17%, 18%, 19%, or 20%. Any dryer system may be used thataccommodates wet feed. For example, a cage mill flash dryer, rotary drumdryer, or ring flash dryer may be used. The resulting dried filter cakeand syrup fuel is collected from the dryer and cooled.

In various embodiments, one or more of the following specific methodsteps may be applied. A delumper is used to reduce the size of filtercake clumps to about 0.5 inch (1.427 cm) or less. Filter cake and syrupare fed separately to a mixing apparatus. Feeding is through spraynozzles. Pre-dried material (either dried filter cake or dried filtercake and syrup mixture) is fed to the mixing apparatus either prior toor concurrently with feeding of filter cake and syrup. The mixed filtercake and syrup passes to a dryer. The filter cake and syrup mixture isflash dried in a flash dryer. The dryer gas entering the dryer has atemperature of between about 225° C. and 350° C. Dryer gas is used inthe dryer that is recompressed, reheated, and recycled to the dryer. Theresulting dried filter cake and syrup fuel is separated from the dryergas stream, cooled, and conveyed to bulk storage. A portion of the driedfilter cake and syrup fuel is added to initial filter cake and syrupfeed streams or to the mixing apparatus prior to addition of the filtercake and syrup.

The filter cake and syrup fuel is burned in a cement kiln containingcement raw material to produce the temperatures needed for cementproduction. The fuel may be burned in any type of cement kiln used inthe cement production process, such as a precalciner, a calciner, and arotary kiln.

The filter cake and syrup fuel may be used in combination with any otherfuel that is used in the cement production process. Examples of otherfuels that may be in a mixture with the filter cake and syrup fuelinclude coal, petroleum coke, and waste materials.

The material produced in the cement kiln is calcined clinker. Thisclinker is collected, cooled, and ground producing cement. Additives maybe mixed with the cement to modify its properties such as gypsum,accelerators, dispersants, strength modifiers, retarders, extenders,weighting agents, fluid-loss control agents, antifoam agents, corrosioninhibitors, and combinations thereof.

An additional material that may be added to cement is ash residue fromburned filter cake and syrup fuel. The filter cake and syrup fuel may beburned in any appropriate burning furnace to produce the ash, such as asteam boiler, hot water boiler, process furnace, or other industrial orcommercial combustion process with suitable emissions controls. The ashmay be used to alter the properties of the cement mixture. In addition,syrup or filter cake that is burned separately produces ash that may beadded to cement. In various embodiments, ash from burned filter cake andsyrup fuel, filter cake, syrup, or any mixture of these materials isadded to cement. In one embodiment a cement composition contains ashfrom burned filter cake and syrup fuel, filter cake, syrup, or anymixture of these materials.

Concrete is typically a mixture of cement, water, and aggregate. Inaddition, ash residue from burned filter cake and syrup fuel may be usedas a supplemental cementitious material in concrete or other cementcontaining materials. In addition, ash residue from burned filter cakeor syrup may be used as a supplemental cementitious material in concreteor other cement containing materials. The ash from burned filter cakeand syrup fuel, filter cake, or syrup may be added in addition tocement, or it may partially replace cement in concrete or other cementcontaining materials. In various embodiments, ash from burned filtercake and syrup fuel, filter cake, syrup, or any mixture of thesematerials is added to a concrete mixture. In one embodiment a concretecomposition contains ash from burned filter cake and syrup fuel, filtercake, syrup or any mixture of these materials.

EXAMPLES

The present invention is further defined in the following Examples. Itshould be understood that these Examples, while indicating preferredembodiments of the invention, are given by way of illustration only.From the above discussion and these Examples, one skilled in the art canascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various uses andconditions.

The meaning of abbreviations used is as follows: “s” is second, “min”means minute(s), “h” of “hr” means hour(s), “μL” or “μl” meansmicroliter(s), “mL” or “ml” means milliliter(s), “L” or “l” meansliter(s), “m” is meter, “nm” means nanometer(s), “mm” meansmillimeter(s), “cm” means centimeter(s), “μm” means micrometer(s), “mM”means millimolar, “M” means molar, “mmol” means millimole(s), “pmole”means micromole(s), “g” means gram(s), “pg” means microgram(s), “mg”means milligram(s), “kg” is kilogram, “rpm” means revolutions perminute, “C” is Centigrade, “ppm” means parts per million, “cP” iscentipoise, “g/l” means grams per liter, “SSU” is Saybolt UniversalViscosity in Seconds.

Saccharification Enzymes

Accellerase® 1500 (A1500) and Multifect® Xylanase are obtained fromDanisco U.S. Inc., Genencor, International (Rochester, N.Y.).

Cellulase and Hemicellulase Production Strain

Strain 229: A Trichoderma reesei strain, derived from RL-P37(Sheir-Neiss and Montenecourt, 1984, Appl. Microbiol. Biotechnol.20:46-53) through mutagenesis and selection for high cellulaseproduction, was co-transformed with the β-glucosidase expressioncassette (cbh1 promoter, T. reesei β-glucosidase1 gene, cbh1 terminator,and amdS marker), and the endoxylanase expression cassette (cbh1promoter, T. reesei xyn3, and cbh1 terminator) using PEG mediatedtransformation (Penttila et al., 1987, Gene 61(2):155-64). Numeroustransformants were isolated and examined for β-glucosidase andendoxylanase production. One transformant, referred to as T. reeseistrain #229, was used in certain studies described herein.

Strain H3A: T. reesei strain #229 was co-transformed with theβ-xylosidase Fv3A expression cassette (cbh1 promoter, Fv3A gene, cbh1terminator, and alsR marker), the β-xylosidase Fv43D expression cassette(egl1 promoter, Fv43D gene, native Fv43D terminator), and the Fv51Aα-arabinofuranosidase expression cassette (egl1 promoter, Fv51A gene,Fv51A native terminator) using electroporation. Transformants wereselected on Vogels agar plates containing chlorimuron ethyl. Numeroustransformants were isolated and examined for β-xylosidase andL-α-arabinofuranosidase production. T. reesei integrated expressionstrain H3A, which recombinantly expresses T. reesei β-glucosidase 1, T.reesei xyn3, Fv3A, Fv51A, and Fv43D was isolated.”

Extra cellular protein produced during fermentation of strain H3A wasseparated from the cell mass by centrifugation, concentrated bymembrane-ultrafiltration through a Millipore 10 kD molecular cut offweight membrane and pH adjusted to 4.8. Total protein was determinedusing a modified Biuret method as modified by Weichselbaum and Gornallusing Bovine Serum Albumin as a calibrator (Weichselbaum, 1960, Amer. J.Clin. Path. 16:40; Gornall et al., 1949 J. Biol. Chem 177:752). This H3Aextracellular protein preparation, called herein H3A protein, was usedas a combination cellulase and hemicellulase preparation effectingcomplex carbohydrate hydrolysis during SSF.

Biocatalyst And Inoculum Preparation

Origin of the Zymomonas mobilis strains for Fermentation

A lignocellulosic biomass hydrolysate fermentation broth may be madeusing alternative biocatalysts. Exemplary strains are are describedbelow. As an alternative, strain ZW658, deposited as ATCC #PTA-7858, maybe used to produce a lignocellulosic biomass hydrolysate fermentationbroth for processing.

Zymomonas mobilis strain ZW705 was produced from strain ZW801-4 by themethods detailed in U.S. Pat. No. 8,247,208, which is hereinincorporated by reference, as briefly restated here. Cultures of Z.mobilis strain ZW801-4 were grown under conditions of stress as follows.ZW801-4 is a recombinant xylose-utilizing strain of Z. mobilis that wasdescribed in U.S. Pat. No. 7,741,119, which is herein incorporated byreference. Strain ZW801-4 was derived from strain ZW800, which wasderived from strain ZW658, all as described in U.S. Pat. No. 7,741,119.ZW658 was constructed by integrating two operons, PgapxylAB andPgaptaltkt, containing four xylose-utilizing genes encoding xyloseisomerase, xylulokinase, transaldolase and transketolase, into thegenome of ZW1 (ATCC #31821) via sequential transposition events, andfollowed by adaptation on selective media containing xylose. ZW658 wasdeposited as ATCC #PTA-7858. In ZW658, the gene encodingglucose-fructose oxidoreductase was insertionally-inactivated usinghost-mediated, double-crossover, homologous recombination andspectinomycin resistance as a selectable marker to create ZW800. Thespectinomycin resistance marker, which was bounded by loxP sites, wasremoved by site specific recombination using Cre recombinase to createZW801-4.

A continuous culture of ZW801-4 was run in 250 ml stirred, pH andtemperature controlled fermentors (Sixfors; Bottmingen, Switzerland).The basal medium for fermentation was 5 g/L yeast extract, 15 mMammonium phosphate, 1 g/L magnesium sulfate, 10 mM sorbitol, 50 g/Lxylose and 50 g/L glucose. Adaptation to growth in the presence of highconcentrations of acetate and ammonia was effected by graduallyincreasing the concentration of ammonium acetate added to the abovecontinuous culture media while maintaining an established growth rate asmeasured by the specific dilution rate over a period of 97 days.Ammonium acetate was increased to a concentration of 160 mM. Furtherincreases in ammonium ion concentration were achieved by addition ofammonium phosphate to a final total ammonium ion concentration of 210 mMby the end of 139 days of continuous culture. Strain ZW705 was isolatedfrom the adapted population by plating to single colonies andamplification of one chosen colony.

Strain AR3 7-31 was produced from strain ZW705 by further adaptation forgrowth in corn cob hydrolysate medium as disclosed in U.S. Pat. No.8,476,048, which is incorporated herein by reference. ZW705 was grown ina turbidostat (U.S. Pat. No. 6,686,194; Heurisko USA, Inc. Newark,Del.), which is a continuous flow culture device where the concentrationof cells in the culture was kept constant by controlling the flow ofmedium into the culture, such that the turbidity of the culture was keptwithin specified narrow limits. Two media were available to the growingculture in the continuous culture device, a resting medium (Medium A)and a challenge medium (Medium B). A culture was grown on resting mediumin a growth chamber to a turbidity set point and then was diluted at adilution rate set to maintain that cell density. Dilution was performedby adding media at a defined volume once every 10 minutes. When theturbidostat entered a media challenge mode, the choice of addingchallenge medium or resting medium was made based on the rate of returnto the set point after the previous media addition. The steady stateconcentration of medium in the growth chamber was a mix of Medium A andMedium B, with the proportions of the two media dependent upon the rateof draw from each medium that allowed maintenance of the set celldensity at the set dilution rate. A sample of cells representative ofthe population in the growth chamber was recovered from the outflow ofthe turbidostat (in a trap chamber) at weekly intervals. The cell samplewas grown once in MRM3G6 medium and saved as a glycerol stock at −80° C.

ZW705 was grown to an arbitrary turbidity set point that dictated thatthe culture use all of the glucose and approximately half of the xylosepresent in the incoming media to meet the set point cell density at theset dilution rate. Using resting medium that was 50% HYAc/YE and 50%MRM3G6.5X4.5NH₄Ac12.3 and challenge medium that was HYAc/YE. A strainisolated after 3 weeks was used in another round of turbidostatadaptation using HYAc/YE as the resting medium and HYAc/YE+9 weight %ethanol as the challenge medium. Strain AR3 7-31 was isolated after 2weeks and was characterized as a strain with improved xylose and glucoseutilization, as well as improved ethanol production, in hydrolysatemedium. By sequence analysis, AR3 7-31 was found to have a mutation inthe Zymomonas mobilis genome ORF encoding a protein havingcharacteristics of a membrane transport protein, and annotated asencoding a fusaric acid resistance protein.

Media

MRM3 contains per liter: yeast extract (10 g), KH₂PO₄ (2 g) andMgSO₄.7H₂O (1 g)

MRM3G6 contains is MRM3 containing 60 g/L glucose

MRM3G6.5X4.5NH₄Ac12.3 is MRM3 containing 65 g/L glucose, 45 g/L xylose,12.3 g/L ammonium acetate

HYAc/YE contains cob hydrolysate from which solids were removed bycentrifugation and that was filter sterilized containing 68 g/L glucose,46 g/L xylose and 5 g/L acetate, supplemented with 6.2 g/L ammoniumacetate and 0.5% yeast extract, adjusted to pH 5.8.

Lignocellulosic Biomass Processing and Fermentation Corn stover ismilled to ⅜″ (0.95 cm). Pretreatment is at 140° C. with 12% NH₃ and 65%solids for 60 min. Saccharification is at 47° C., pH 5.3, with 7.8 mg/gglucan+xylan of an enzyme consortium, for 96 hr. Saccharificationenzymes are a mix of cellulases and hemicellulases expressed in aTrichoderma reesei strain H3A as described above. The resultinghydrolysate is used in fermentation. 10 mM sorbitol is added to thehydrolysate making the fermentation medium, and the pH is adjusted to5.8.

For the seed, first frozen strain Zymomonas mobilis AR3 7-31 stock isgrown in MRM3G6 (10 g/L BBL yeast extract, 2 g/L KH₂PO₄, 1 g/LMgSO₄*7H₂O, 60 g/L glucose) at 33° C., without shaking for 8 hr as arevival culture. MRM3G10 medium (same as MRM3G6 but with 100 g/Lglucose) is inoculated with revival culture, and incubated at 33° C.with shaking for 14-16 hr. Growth is to an OD₆₀₀ between 1.5 and 3.1.The entire culture is used to inoculate a seed fermenter to an initialOD₆₀₀ of approximately 0.05.

The seed fermentation is carried out in 10 g/L yeast extract, 2 g/LKH₂PO₄, 5 g/L MgSO₄*7H₂O, 10 mM sorbitol, and 150 g/L glucose. Seedfermentation is performed at 33° C. and pH 5.5. Seed is harvested afterfirst observation of glucose reduction to less than 50 g/L, with glucosemeasured by using a YSI 2700 SELECT™ Biochemistry Analyzer (YSI LifeSciences; Yellow Springs, Ohio).

The seed is added to the hydrolysate medium in the fermenter.Fermentations are carried out at 30° C.-33° C. for 48-72 hr.

Lignocellulosic Syrup and Filter Cake

The fermentation broth is distilled to recover ethanol and the remainingwhole stillage is filtered using a membrane filter press. The liquidfraction is passed through a multi-effect evaporator train removingoverhead water, and producing a lignocellulosic syrup. The solidsfraction is a lignocellulosic filter cake.

Example 1 Preparation of Filter Cake and Syrup Fuel

Filter cake and syrup that were prepared as described in General Methodswere combined in a mixer/dryer system that provides wet feedconditioning and flash drying capabilities for the filter cake and syrupco-products. The filter cake had a moisture content of about 45%. Thesyrup had a moisture content of about 45%-50%. The filter cake was sizereduced in a delumper to a size of 0.5 inch (2.54 cm) or less. Pre-driedfilter cake and syrup mixture with moisture content of 9.5%-17%, filtercake, and syrup were fed separately to a paddle mixer from spraynozzles. Filter cake was fed at 135-250 lb/hr. Syrup was fed at 90-182lb/hr, and dried filter cake was fed at 1070-2645 lb/hr.

After mixing, the contents were passed to a cage mill flash dryer andflash dried using dryer gas at about 225° C. to 250° C. to a moisturecontent between about 9.5% and 17%. The dried filter cake and syrup fuelproduct was then separated from the dryer gas stream. The gas wasrecompressed and reheated for recycle. A portion of the dryer gas waspurged and treated for VOC reduction. A portion of the dried filter cakeand syrup was separated to use as recycle solids (pre-dried filter cakeand syrup mixture) in additional runs instead of pre-dried filter cake.The dried filter cake and syrup fuel product was cooled and conveyed tobulk storage.

Example 2 Prophetic Fueling a Cement Process Using Filter Cake and SyrupFuel

Filter cake and syrup fuel prepared as described in Example 1 istransported, and delivered to the fuel handling system at a cementmaking facility, where it is stored. The fuel is metered from thestorage bin and conveyed pneumatically to feed points in a pre-calciner,calciner or is cement kiln and burned as fuel in the cement productionprocess. Use of this fuel offsets use of fossil fuel or otheralternative fuels to provide heat input required for cement production.

What is claimed is:
 1. A cement composition comprising ash from burnedmaterial selected from the group consisting of filter cake and syrupfuel, filter cake, syrup, and mixtures thereof.
 2. A concretecomposition comprising ash from burned material selected from the groupconsisting of filter cake and syrup fuel, filter cake, syrup, andmixtures thereof.
 3. The cement composition of claim 1 wherein thefilter cake and syrup fuel, the filter cake, and the syrup are alllignocellulosic comprising both lignin and cellulose.
 4. The cementcomposition of claim 1 wherein the filter cake comprises: is a) fromabout 35% to about 65% moisture; b) from about 20% to about 75%volatiles; c) from about 35% to about 65% solids; d) from about 1% toabout 30% ash content; and e) from about 5% to about 20% fixed carbon;wherein the filter cake has an energy value of about 2,000 to about9,000 BTU/lb.
 5. The cement composition of claim 1 wherein the syrupcomprises: a) from about 40% to about 70% solids; b) from about 10 g/lto about 30 g/l of acetamide; and c) at least about 40 g/l of sugars;wherein the syrup has a density of about 1 to about 2 g/cm³ and aviscosity of less than 500 SSU at 100° F. (38° C.).
 6. The cementcomposition of claim 1 wherein the syrup comprises at least about 5 g/lof ammonia.
 7. The cement composition of claim 1 wherein the filter cakeand syrup fuel, the filter cake, and the syrup have a moisture contentof between 8% and 20%.
 8. The cement composition of claim 1 furthercomprising burned cement raw material selected from the group consistingof limestone, clay, shale, sand, bauxite, iron ore, fly ash, slag, andcombinations thereof.
 9. The cement composition of claim 8 wherein thecement raw material is limestone.
 10. The concrete composition of claim2 wherein the filter cake and syrup fuel, the filter cake, and the syrupare all lignocellulosic comprising both lignin and cellulose.
 11. Theconcrete composition of claim 2 wherein the filter cake comprises: a)from about 35% to about 65% moisture; b) from about 20% to about 75%volatiles; c) from about 35% to about 65% solids; d) from about 1% toabout 30% ash content; and e) from about 5% to about 20% fixed carbon;wherein the filter cake has an energy value of about 2,000 to about9,000 BTU/lb.
 12. The concrete composition of claim 2 wherein the syrupcomprises: a) from about 40% to about 70% solids; b) from about 10 g/lto about 30 g/l of acetamide; and c) at least about 40 g/l of sugars;wherein the syrup has a density of about 1 to about 2 g/cm³ and aviscosity of less than 500 SSU at 100° F. (38° C.).
 13. The concretecomposition of claim 2 wherein the syrup comprises at least about 5 g/lof ammonia.
 14. The concrete composition of claim 2 wherein the filtercake and syrup fuel, the filter cake, and the syrup have a moisturecontent of between 8% and 20%.